Do you know how to make things louder even if its made to be quiet e.g. a hybrid car

Question: Do you know how to make things louder even if its made to be quiet e.g. a hybrid car
- Keywords:
  car,
  loud,
  quiet
Asked by 538aerf28 to Michael on 15 Jun 2016.
- Michael Carley answered on 15 Jun 2016:
  
  Yes, although the easiest way to do it is usually to put a loudspeaker on. This is one area where we sometimes work with psychologists to study which sound is most useful to help people understand where a car is coming from so that they don’t step into the traffic in front of it by accident.

Question: Do you know how to make things louder even if its made to be quiet e.g. a hybrid car